WHIDBEY ISLAND, Wash. – One person has been found dead and nine people are missing after a seaplane crashed west of Whidbey Island Sunday afternoon.

The Coast Guard says 10 people, including a child, were on board when the plane went down in Mutiny Bay at about 3 p.m.

The plane took off from Friday Harbor and was bound for Renton Municipal Airport.

A massive search continues involving a rescue helicopter, fixed wing aircraft, two Coast Guard cutters and two Response Boats.

The Coast Guard says the cause of the crash remains unknown at this time.

Identities of those on board and the plane’s owners haven’t been released.